Thermostat valve means



Oct. 9, 1956 E. L. MAYO THERMOSTAT VALVE MEANS Filed April 8, 1953 2 Sheets-Sheet 1 w 0 E 9 1. A w W7 w m 2.. w i w 7 J Y 1 H N l Mm M ii h W; im j 6 3 fi w j j Oct. 9, 1956 E, M 2,765,983

THERMOSTAT VALVE MEANS Filed April 8, 1953 2 Sheets-Sheet 2 IN V EN TOR.

THERMosrAr vALvn MEANS Edward L. Mayo, Cleveland, Ohio, assignor to The Bishop & Babcock Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application April 8, 1953, Serial No. 347,528 Claims. (c1. 236-34) The present invention relates to thermostat valve means and, particularly, to thermostats for liquid cooled internal combustion engines.

Most internal combustion engines, particularly those employed in automotive vehicles, are equipped with a liquid cooling system comprising liquid passageways formed in the block of the engine about the cylinders, a heat exchanger in the form of a radiator disposed for passage of air therethrough to cool the liquid, and a pump for circulating liquid, usually water, through the engine block and the radiator. As is known, internal combustion engines have optimtnn operating temperatures, which should be attained as soon as possible after starting the engine and which should be maintained during engine operation. To maintain operating temperatures, the cooling system is designed to provide proper cooling of the engine once the operating temperature is attained. However, the engine cannot rapidly come up to operating temperature if the cooling system is continuously operating at full effectiveness. In view of these factors, it has become con ventional practice to incorporate a thermostat valve in the cooling system to prevent flow of cooling liquid through the heat exchanger or radiator until the engine attains operating temperature, at which time the valve opens to accommodate liquid flow and an engine cooling effect. The valve may open either partially to accommodate such flow as will maintain a predetermined temperature of the cooling medium in the engine block, and thus of the engine, or may open fully to accommodate full cooling effect.

Conventional thermostat valves adapted for the purposes above described comprise, basically, a stationary support defining a valve port adapted to be mounted in the cooling system, a temperature responsive unit, normally a liquid filled bellows, mounted on the stationary support to be positioned in the path of cooling liquid flow to the inlet side of the valve port, and a valve member disposed to the outlet side of the valve port and operatively connected to the temperature responsive unit for actuation thereby to control flow through the valve port. In conventional cooling systems, the circulating pump has a relatively low pressure output and to balance the valve against static pressure so that the same is truly temperature responsive, it has been the practice to expose equal areas of the movable part of the bellows or temperature responsive unit and the valve member to fluid pressure so that the two areas offset one another and thus nullify the pressure effect. For low pump output pressures, this has been entirely effective.

However, due to the recent advent of increased compression ratios, decreased radiator exposures, and for other reasons, manufacturers of internal combustion engines have been forced to increase the pressure and rate of flow in the cooling system to offset increased engine temperatures so as to maintain the engine at proper operating temperature. Specifically, the circulating pump outlet pressure has been increased substantially over pre- 2,755,983 Patented Got. 9, 1956 viously adopted standards. Under increased pressures, it will be obvious that the thermostat valve structures heretofore employed will nullify static pressure effect, but that the same will not nullify the dynamic or impact pressure effect resulting from high velocity flow. Because of this, conventional thermostat valves cannot be truly temperature responsive in the new engines, but instead are opened, when not desired, by impact or velocity pressure, and thus fail to perform their intended function.

It is the primary object of the present invention to provide improved thermostat valve means that are not pressure responsive, even to velocity impact, and that are truly temperature responsive.

As will be appreciated from the foregoing, static pressure conditions in a cooling system may readily be nullified as the same effect the thermostat by exposing equal areas of the bellows and the valve member to the pressure condition. It is the velocity pressure component of the pump output that must be nullified or eliminated to render the thermostat responsive solely to variations in the temperature of the cooling medium. In accordance with this observation, it is an object of the present invention to provide improved thermostats including means for eliminating or rendering static, as far as the thermostat is concerned, any component of dynamic pressure energy in the cooling medium to be controlled by the thermostat.

More specifically, it is an object of the present invention to provide improved thermostat valve means including means, which I shall term statofying means, adapted to nullify or render static, as to the thermostat means, dynamic fluid forces brought to bear on the valve means.

In accordance with the foregoing objects, I provide, according to the present invention, thermostat valve means formed basically according to conventional construction, but incorporating the statofying means referred to, the statofying means preferably comprising a stationary wall disposed in the path of fluid flow between the bellows or temperature responsive unit and the valve member to shield the valve member from velocity flow, at least in the direction of valve movement. The statofying means also preferably includes valve ports adjacent said wall angularly related to the normal direction of flow and to the portion of the valve exposed to nullify static pressures, whereby the valve member is not exposed to dynamic pressure influence. In such construction, the temperature responsive unit is not subject or sensible to the velocity pressure component, the said wall absorbs the velocity pressure component and protects or shields the valve member therefrom, and the valve ports are disposed so as to avoid any application of dynamic force to the valve member in a direction longitudinally of or parallel to the direction of valve member movement. Thus, dynamic influence is nullified and the valve is subject only to static pressures. To nullify static pressure influence, conventional practice as above described is resorted to. Accordingly, means formed according to the present invention are not sensitive to either dynamic or static pressure and are responsive solely to variations in the temperature of the medium to be controlled.

A further object of the invention is the provision of improved thermostat valve means of the character described that are economical of manufacture and assembly, sturdy and practical in use, and capable of performing eificient service for prolonged periods of use.

Other objects and advantages of the present invention will become apparent in the following detailed description of preferred embodiments of the invention.

Now, in order to acquaint those skilled in the art with one manner of constructing and using the thermostat it will be appreciated that thermostat valve.

valve means of the present invention, 1 shall describe, in connection with the accompanying drawings, preferred embodiments of my invention and a manner of making and using the same.

in the drawings:

Figure l is a vertical cross-sectional view of one embodiment of the thermostat valve means of the invention as mounted in an engine cooling system, portions of the cooling system being shown fragmentarily, the valve means being of the single valve type and being shown in closed position;

Figure 2 is a side elevation of the valve means shown in Figure l, the view being taken at right angles to Figure 1 and showing the valve in open position.

Figure 3 is a cross-sectional view similar to Figure l of a second embodiment of the thermostat valve means of the invention, the valve means being of the double valve type and being shown with the by-pass valve open and the radiator valve closed; and

Figure 4 is a vertical cross-sectional view of the valve means shown in Figure 3, the view being taken at approximately 30 to the view of Figure 3 and showing the bypass valve closed and the radiator valve open.

The construction of internal combustion engines and the cooling system thereof is well known and forms no part of the present invention. Accordingly, only those portions of the engine in which the thermostat valve means is to be mounted have been shown herein. Briefly, however, engine cooling systems are of two basic types. In one, a pump is provided adjacent the lower tank of the radiator for circulating water or other liquids through the engine block and radiator, and the thermostat valve when closed prohibits such how and merely retains the water in the engine block without flow. In the second type, generally the same construction is followed, but a bypass is incorporated in the engine block leading from adjacent the thermostat valve to the pump in-take so that the water originally in the engine block may be circulated through the block only when the thermostat valve closes olf flow to the radiator. controlled when flow to the radiator is accommodated by the thermostat valve. The thermostat valve means shown in Figures 1 and 2 hereof is adapted for use in cooling systems of the said one type and, as will be appreciated, requires only one valve member to control flow of liquid from the engine block to the radiator. A thermostat valve means adapted for use in cooling systems of the second type is shown in Figures 3 and 4, wherein the valve means include two valve members, one for controlling flow from the engine block to the radiator and one for controlling the by-pass.

Referring now to Figures 1 and 2 of the drawings, 1 have shown a portion of an engine block at 10, which portion includes a passageway 12 constituting the cooling system outlet from the engine block. A rigid conduit 14 including a bulbous portion 16 is adapted to be mounted in communication with the passageway 12 in the block 10 by means of bolts (not shown) extending through a flange 18 at the base of the conduit 14 and threaded into the engine block it). A gasket 29 is confined between the engine block 19 and conduit 14 to prevent leakage of liquid at this connection. As is well known, the free end of the conduit 14 is adapted for the reception of a flexible conduit establishing communication between the engine block and a heat exchanging radiator. in view of the foregoing, it will be appreciated that the relationship described is such that the cooling system falls into the first type referred to hereinbefore.

The thermostat valve means of the present invention, as shown in Figures 1 and 2, comprises a circular mounting plate 22 having a radially extending flange 24 adapted to be confined between the engine block 18 and the conduit 14, the base of conduit 14 being provided with a recess 26 adapted for the reception of the flange 24 so that the mounting plate is confined between the gasket 29 In this latter type, the by-pass must be (ill and the conduit 14 to provide a stationary support for the thermostat valve means. The mounting plate 22 also defines a valve port or seat portion, indicated generally at 28, to be described in greater detail hereinafter. A bellows support 39 depends from the mounting plate 22, the support comprising a pair of diametrically opposed legs or straps 32, each abutting the lower surface of the plate 22 and having a reduced extension 34 passing through a suitable slot or the like in the plate 22 and secured thereto by swaging the extension over the top of the plate, and a generally circular base portion 36 extending between the legs 32 at the bottoms thereof. The base 36 of the support 36 preferably includes an upwardly extending circumferential flange portion 38 defining a cup adapted for the reception of one end of a bellows 4-0.

The bellows as is preferably secured to the cup portion of the support 39 by flowing solder about the edge of the flange 38.

The bellows db extends upwardly from the base 36 between the legs 32 and at the upper end thereof is provided with a rigid top plate 42 suitably sweated or otherwise secured to the bellows. The top plate 42 is preferably annular and includes an annular rib 44 to rigidity the same. At the central portion thereof, the top plate is provided with an opening within which a hollow stem 46 is secured. The stem 46 is preferably tubular and serves the dual function of a filler tube for the bellows and a valve stem. The stern 45 may be suitably secured to the top plate 42 by providing a reduced extension on the stem capable of being passed through the aperture in the top plate, and by swaging or spreading the lower end of the extension outwardly, as indicated at 48, prior to assembly of the top plate and the bellows. Such spreading of the tube will provide a liquid tight seal between the top plate and the tube, or sealing may be effected by means of solder or the like.

After the bellows has been filled, by pouring a suitable thermosensitive fluid through the tube 46, the upper end of the tube, and thus the bellows, is closed by means of a sealing plug 56 suitably secured in the neck of the tube, all as is well known. The upper end of the stem or tube 46 is externally threaded, as at 52, for the adjustable reception of a valve member, indicated generally at 54, which will be described in greater detail hereinafter. After adjustment, the valve member 54 is preferably fixed to the stem 46, suitably by soldering, as indicated at 56.

As thus far described, the thermostat valve means is substantially conventional. in use, the inverted cupshaped plate 22 is disposed generally transversely of the normal path of liquid flow and defines an inlet to the open or lower side thereof and an outlet spaced from the inlet. The bellows as is disposed in the path of flow of the medium to be controlled and to the inlet side of the plate 22. As the temperature of the medium rises and falls, the

1 valve member 54 will be moved away from and toward its seat, respectively, in a conventional manner, the bellows and the filling therefor being designed and calibrated to maintain a predetermined temperature of the cooling medium in the system. The bulbous portion 16 of the conduit 14 forms a housing for the upper portion of the valve accommodating free movement of the valve member and stem. All components of the valve are preferably formed of copper or brass so as to be non-rusting and non-corroding in use.

in the particular embodiment of the invention shown in Figures 1 and 2, the statofying means of the present invention is incorporated in the valve port portion 28 of the mounting plate 22 and in the valve member 54. Specifically, the mounting plate 22 is in the form of an inverted cup having portions of increasing diameter from the top to the bottom thereof. At the upper portion thereof, the plate 22 includes a generally frusto-conical side wall portion 53 having a plurality of openings fill therein defining a valve port. Preferably, the openings 6% are large so that the side wall 58 constitutes merely a plurality of upstanding inclined legs 62. The plate 22 is provided at the top thereof with Wall 64, supported by th legs 62, having a central aperture therethrough for passage of the valve stem 46. Preferably, the wall 64 is inclined downwardly toward its center, so as to present a generally convex lower surface, and the material thereof is rolled about the central aperture, as at 66, to present a smooth surface to the stem 46 to avoid binding on the stem. This wall has been referred to hereinbefore as a wall shielding the valve member. While the wall is ac tually apertured for the passage of the stem 46, it will be appreciated, as the description proceeds, that the wall 64 together with the stem 46 presents a generally imperforate area shielding the valve member 54. To this extent then, the wall 64 is imperforate. Preferably, the portion 66 of the wall 64 about the stem is slightly larger than the stem to accommodate a slow or relatively restricted flow of liquid, without velocity impact, past the wall 64.

As formed according to the present invention, the valve member 54 comprises an inverted cup-shaped member adapted to fit over the top of the plate 22. In particular, the valve member 54 includes an imperforate frustoconical side Wall portion 68 adapted to fit over the frustoconical wall portion 58 of the plate 22 to close the openings or valve ports 6t) in the wall 58. At the base of the wall 58, the plate 22 presents a radial flange defining a generally horizontal valve seat 70. The cup defined by the valve member is deeper than the cup defined by the walls 58 and 64 so that the lower edge of the wall 68 of the valve member is adapted to seat upon the flange 70 to close the valve to fluid flow. While the frusto-conical or tapered formations of the wall portions of the valve member and the valve port member are preferred, since such structure accommodates automatic centering and accurate seating of the valve member without sticking or binding, other wall forms may be employed as desired, such as cylindrical for example. As will presently appear, the importance of the valve port member design is to avoid or prevent velocity impact on the valve member in such manner as to bias the valve to open position. To limit opening movement of the valve, a stop member 72 is secured to the valve stem 46 to engage the wall 64 at the position wherein the valve is fully opened, as is shown in Figure 2. The stop 72 preferably comprises a C-ring fitted in a circumferential groove provided in the valve stem 46. As will be appreciated, opening movement of the valve member is limited by the stop 72 engaging the wall 64, and closing movement is limited by the lower edge of the valve member 54 engaging its seat.

From the foregoing, it will be appreciated that the construction and assembly of the valve of the present invention is extremely economical. All valve components, with the exception of the bellows 40, the filling tube 46, and the plug 50 suitably comprise metal stampings to facilitate the economical manufacture of the thermostat valve means.

Having thus described a preferred embodiment of the valve means of the present invention, I shall now describe the purposes and operational characteristics of the valve means. From such description, it will be apparent that the particular embodiment disclosed is capable of modification within the scope of the invention. In use, water or other cooling liquid being forced through the engine cooling system at relatively high pressures and speeds, such as those accompanying a pump output pressure in the order of 10 pounds per square inch, will be forced through the passageway 12 in the engine block toward the thermostat valve means. Due to the stationary mounting thereof, the temperature responsive means or bellows 46 will not sense the velocity impact or pressure of the liquid. Since the top plate 42 of the bellows does not face in the direction of liquid flow, it will not be responsive to velocity impact. However, if the wall 64 were not provided to shield the valve member 54, the

same would be subject to the velocity impact or pressure and would be biased to open position. Thus, velocity pressure would normally vibrate the valve member rendering the thermostat valve means incapable of performing its intended functions. To eliminate or nullify the velocity or impact effect, the present invention provides statofying means in the form of the end wall 64 disposed generally transversely of the direction of valve member movement, and the valve ports 60 disposed in angular relation to the direction of movement of the valve member. Specifically, the liquid rushing toward the valve member 54 will engage the end Wall 64 and Will be deflected thereby laterally outward. The downward inclination of the central portion of the wall 64 is such as to accommodate the lateral deflection of the liquid. The liquid may then flow through the ports 60 and engage the side Wall 68 of the valve member 54. Thus, any velocity energy remaining in the liquid after deflection by the wall 64 will be exerted in a radial direction on the valve member, in which direction it can exert no valve operating force. In effect then, the wall 64 shields the valve member from velocity flow in the direction of valve movement and the valve ports are disposed to prevent exertion of velocity forces in the direction of valve movement. Thus, as far as the thermostat valve means is concerned, the velocity impact or pressure component of the pump discharge is nullified or rendered static, whereby the same can have no disadvantageous effect on the valve means.

To compensate for, and actually to nullify, static pressure in the system as that pressure affects the thermostat, substantially equal but oppositely disposed areas of a movable part of the temperature responsive means or bellows 40 and the valve member 54 are exposed to fluid pressure. Specifically, the top 42 of the bellows and the lower surface of the valve member 54 are exposed to fluid or liquid pressure, the areas of the two members being substantially equal. To accommodate fluid flow to the under surface of the valve member, without velocity impact, relatively restricted by-passes are provided by forming the aperture in the shielding wall 64 slightly larger than the diameter of the stem 46 and by forming the wall 68 of the valve member 54 of a slightly larger size, and preferably at a slightly steeper angle of inclination, than the wall 58 defining the valve ports. Thus, the entire lower surface of the valve member is exposed to static pressure conditions to offset static pressure influence on the bellows 40.

In view of the foregoing, it will be appreciated that the present invention provides improved thermostat valve means including What I term statofying means, in the form of means for shielding the valve member from velocity flow in the direction of valve movement and valve port means angularly related to the direction of valve movement, and wherein all pressures ordinarily capable of affecting valve operation are eliminated or nullified, whereby the valve means is responsive solely to variations in the temperature of the medium to be controlled. Whether the valve be closed as shown in Figure 1, fully open as shown in Figure 2, or partially open, the described relationship and operational characteristics will exist.

Turning now to Figures 3 and 4, I have shown a second embodiment of the thermostat valve means of the present invention particularly adapted for use in cooling systems of the by-pass type, and showing the same as mounted in a portion of such system. In particular, I have shown a portion of an engine block which portion includes a liquid passageway 82 comprising the liquid outlet from the block. A fitting 84 having a chamber 86 therein is adapted to be secured to the block 80, suitably by means of bolts 88 extending through a flange 90 at the base of the fitting, with the chamber 86 in communication with the passageway 82. Preferably, a gasket 92 is confined between the block and the fitting to prevent leakage of liquid. The fitting 84 is formed with a flange 94 therein '7 defining the chamber 86, and a pair of passageways 96 and 98 communicating with the chamber 86 from above and below the flange 94, respectively. The passage 96 suitably leads to the radiator of the cooling system, and the passage $8 comprises a by-pass to the circulating pump inlet as has been described hereinbefore.

The thermostat valve means of the invention, as shown in Figures 3 and 4, comprises a pair of stationary supporting members ltlil and 182, one of which includes a radial flange N4 adapted to fit in a recess 1% the base of the fitting 84 so as to be confined between the gasket 92 and the fitting. For the time being, the upper stationary member 100 will be referred to merely as being substantially cylindrical and including the flange 194. The lower stationary member 192 is cup-shaped and includes a pair of diametrically opposed flanges 1'38 which ext first radially outward and then substantially longitudinally upward to terminate in mounting tabs 119 having apertures therein. The upper stationary member lilti is provided at diametrically opposed points adjacent the flange 104 thereof with similar apertures whereby the stationary members may be secured together by the passage of rivets or like fasteners 114 through the aligned apertures of the two members.

The cup-shaped lower member 102 is adapted for the reception of a bellows 116, the lower end of the bellows being secured to the base wall of the member m2. Preferably, the bellows is secured to the base of the member 102 by providing apertures 118 in the walls of the member 192 adjacent its base and by flowing solder through said apertures. The bellows 116 is closed at its upper end by means of a rigid plate 12%? suitably sweated or otherwise secured to the bellows. The plate 129 includes an annular rigidifying rib 122 and a plurality of radially extending arms 124 which carry an upstanding generally cylindrical by-pass valve member 126 at the outer ends thereof. Preferably, the plate 128, arms 124 and valve member 126 are integrally formed, the arms comprising a spider connection between the plate and the valve member. At the central portion thereof, the plate 12% is provided with an aperture within which a hollow stem 12% is positioned, the stem being secured to the plate in sealed relation by swaging portions of a reduced end portion of the stem outwardly against the lower surface of the plate 120, as is indicated at 130. As in the previous embodiment, the stem 128 serves the dual function of a filling tube for the bellows and a valve stem. The stem 123 extends upwardly from the plate 12b through the chamber 86, past the flange 94 and well into the passage 96 in the fitting 84.

After the bellows has been filled with a thermosensitive fluid, the same is closed by inserting a suitable plug 132 in the neck of the stem 123. At the upper end thereof, the stem 125% is provided with an external thread 134 whereby the same is adapted for the adjustable reception of a valve member K6, the valve member being fixed to the stem after adjustment by means of solder or the like, as is indicated at 133. Thus, it will be appreciated that the stern 25 carries and rigidly connects a pair of spaced valve members 1'26 and 136.

Considering now the upper stationary mounting member 169, it is seen that the same comprises, generally, an inverted cup presenting increasing diameters from the top to the bottom thereof and that the same extends upwardly hrough the chamber as, past the flange 94, and into the passage 95 in the fitting 84. Adjacent the flange he, the mounting member 161? includes a radial wall portion 1 2% adapted to seat against the lower surface of the flange 9d and eoopearting with the flange 94 to separate the mounting member into separate upper and lower valve chambers 142 and 144, respectively. Preferably, a gasket 146 is confined between the flange d4- and the wall ten of the mounting member.

Between the flange 94 and the base of the fitting 84, the mounting member 100 defines the valve chamber 144,

which comprises a by-pass valve chamber. As shown, the member at this point includes a frusto-conical side wall portion 148 encircling the valve member 126 and having a plurality of openings 15% adjacent the upper end thereof defining a valve port, the port establishing communication between the interior of the member 1% and the by-pass passageway 98. The by-pass valve member 126 in actuality comprises a frusto-conical wall adapted to engage the frusto-conical wall 143 of the in mber adjacent the upper portion thereof, that is, around the ports 154 to close said ports or to control flow of liquid therethrough. Since the valve 126 is adapted to engage the upper portion of the wall 148 to close the by-pass ports 15%, as is shown in Figure 4, the will be spaced from the wall M8 when open to mmodate free flow of liquid, as is shown in Figure 3. to tie particular inclination or taper of the walls 148 and 126 shown, the valve member wall 126 is cut away or slotted, as at 152, to accommodate the mounting tabs il of the lower stationary member 132 when the valve member 126 is in open position. To accommodate such slotting of the valve member without accommodating leakage when the by-pass valve is closed, the wall 143 in which the ports 156 are provided is solid, or imperforate, throughout the area thereof above the tabs 110, whereby the slotted portions of the by-pass valve are not required to close a port.

The portion of the mounting member we extending through the flange $4 of the fitting S4 is preferably substantially cylindrical and at the upper edge thereof includes a radial flange defining a horizontal ledge or valve seat 154. Above the valve seat, the member lid) is preferably of inverted cup shape and presents a frusto-conical wall 156 having a plurality of ports or openings 15S therein. Preferably, the ports 15% are large so that the wall 155 in effect is reduced to a plurality of upstanding inclined legs 16%. The legs 16! support a top wall 162 which preferably is inclined downwardly towards its center to define a generally convex lower surface. At the center portion of the wall 162, an aperture is provided, the wall being rolled about the aperture, as is indicated at 164. The aperture is adapted for the free passage of the valve stem 28 and the rolled portion the of the wall presents a smooth surface accommodating non-binding movement of the stem through the aperture.

The valve member 136 preferably comprises an inverted cup presenting a frusto-conical wall 155 adapted to encircle the wall 156 and the ports 15% to control flow therethrough. The valve member 136 comprises a cup that is deeper than the cup defined by the walls 156 and 162 so that the lower edge of the wall r66 of the valve 136 is adapted to seat on the ledge 154 to close otl communication from the interior of the valve means to the radiator passageway 95 provided in the fitting 84. From the foregoing, it will be appreciated that the formation of the upper valve unit of the present embodiment of the invention is substantially the same as that of the embodiment of the invention described hereinbefore.

In the formation of the valve, it is preferred that the wall portions 125, 148, 156 and 166 be frusto-couical since such formation leads to automatic centering and accurate seating of the valve members without binding. However, other formations may be employed as desired. In the case of the valve .126 and the wall 146, the lower or bypass valve unit, the taper of the two walls is the same. However, in the case of the upper valve unit, the taper of the valve member wall 165 is preferably steeper than that of the valve port member well 156. As in the embodiment of the invention previously described, sub stantially all elements of the valve means are metal stampings thus providing economy of manufacture, and all elements are preferably formed of brass or copper so as to be non-rusting nad non-corroding.

In use, the thermostat valve of the present invention is adapted to be installed in an engine cooling system in the manner described and shown, with the temperature responsive unit or bellows disposed in the path of liquid flow. The stationary member 100 is disposed generally transversely of the normal path of flow and defines an inlet to the lower side thereof and a pair of spaced radial outlets, the ports 150 and 153, above the inlet. The lower valve unit, that is the valve member 126 and the ports is adapted to control flow to the by-pass passageway 98 and the upper valve unit, that is the valve member 136 and the ports 158, is adapted to control flow to the radiator passageway 96. The spacing between the valve members 126 and 136, as rigidly connected by the stem 128, is greater than the spacing between the outlet ports 150 and 158, respectively, so that when one valve is closed the other is open. When the cooling medium in the system is below the predetermined temperature for which the thermostat is calibrated, the valve members will be disposed as shown in Figure 3 wherein the by-pass ports 150 are open and the radiator valve is closed, the same being seated on the ledge or valve seat 154. In such position, liquid flowing through the engine block and passageways 82 and 98 under the influence of a circulating pump discharge in the order of 10 pounds per square inch will exert both static and velocity impact pressures on the thermostat valve means. As to static pressures, the valve means presents a balanced condition. First, the static pressure exerted on the bellows is reflected by the upper area of the plate 129. Such pressure efltect is offset or nullified by exposure of the lower surface of the upper valve member 136 to the static pressure of the liquid. Specifically, relatively restricted communication is provided to the lower surface of the valve 136 through the top wall 162 between the stem 128 and the rim 164 and through the ports 158 due to the steeper inclination or taper of the valve member side wall. The lower valve member 126 and the arms 124 present equal upper and lower areas exposed to fluid flow so that static pressures thereon are automatically counterbalanced and thus nullified.

Considering velocity impact or pressure, it will be appreciated that the lower valve 126 presents substantially no area to be acted upon in the direction of valve movement, except a very minor edge portion. Any component of dynamic force exerted laterally of the valve will not eifect its operation. Likewise, the arms 124 present very little obstruction to velocity flow. Accordingly, it will be appreciated that the exposure of the lower valve member 126 to velocity impact is so small as to result in a negli ible force application in the direction of valve movement. Thus, the lower valve to all practical effect presents a balanced condition both as to static and dynamic pressures. The dynamic or velocity pressure effect on the upper valve member 136 is the same as that described hereinbefore with respect to the valve member of the embodiment of the invention shown in Figures 1 and 2. Specifically, if the wall 162 were not provided, the lower surface of the valve 136 would be subject to velocity impact and would be biased off its seat thereby. However, the wall 162 shields the valve member from velocity flow and directs the flow laterally outward, in which direction the velocity flow cannot exert a valve actuating force. The disposition of the outlet ports 158 in angular relation to the direction of valve movement, generally radially of the valve, prevents flow in such direction as to effect valve movement. Thus, the wall 162 and the disposition of the ports 158 comprise means, which .1 term statofying means, for rendering the fluid forces entirely static as far as the valve means is concerned. As pointed out, static forces are nullified in the construction described. Thus, the valve means of the invention is responsive solely to variations in the temperature of the medium to be controlled.

As the temperature of the cooling medium in the engine cooling system rises, the thermosensitive fluid in the bellows will expand, thus expanding the bellows to move the valve stem upwardly. As the stem 128 moves up-' wardly, the lower valve 126 moves toward the ports to close the same, and thus to close off flow to the by-pass passageway 98. At the same time, the upper valve 136 will be unseated to establish communication between the passageway 82 in the engine block and the passageway 96 in the fitting 84 leading to the radiator. When the cooling medium in the system attains the temperature for which the temperature responsive unit is calibrated, the lower valve 126 will be moved to fully closed position and the upper valve 136 will be moved to fully open position, as is shown in Figure 4. Upward movement to open the upper valve will be limited by engagement of the lower valve 126 with its seat, the wall 148, and downward movement to close the upper valve will be limited by engagement of the valve 136 with its seat 154. In all positions of valve movement, the balanced pressure conditions described hereinbefore will be maintained.

From the foregoing, it will be appreciated that the present invention, in both embodiments, provides an improved thermostat valve means that is insensitive to static pressure conditions, insensitive to high velocity flow, and responsive solely to variations in the temperature of the medium to be controlled. The primary feature of the present invention resides in the statofying means which comprises, principally, means for shielding the valve memher from velocity flow in the direction of valve movement. Such shielding means serves the purpose of dissipating the velocity energy effect of liquid flow and/or of deflecting velocity flow in a direction such that the same will have no effect on the valve member in the direction of valve movement. Thus, the shielding means, the statofying means, renders all forces exerted on the valve means static as far as the valve means is concerned or is able to sense, the valve being designed to nullify static pressure conditions. Secondly, the statofying means includes valve port means disposed to direct fluid flow in a direction other than the direction of valve movement, whereby forces attendant upon velocity flow are not exerted in the direction of valve movement and thus are nullified as far as the valve member is able to sense the same.

While I have described what I regard to be preferred embodiments of my invention, it will be appreciated that various modifications and changes may be made therein without departing from the scope of the invention, as defined by the appended claims.

I claim:

1. A thermostat valve comprising a frame including a cup-shaped portion having a valve port in the side wall thereof, a cup-shaped valve member of a size larger than said portion of said frame freely slidable on said portion, the walls of said valve member being freely spaced from the walls of said portion of said frame, said frame including a valve seat encircling said cup-shaped portion adjacent the open end thereof, said valve member normally seating at its open end on said seat to close the valve, the base wall of said portion of said frame having an opening therethrough, and a temperature responsive unit mounted on said frame to be disposed directly in the path of fluid flow of the medium to be controlled and including a stem extending freely through said opening in the base wall of said portion and connected to the base wall of said valve member, the opposed surfaces of said valve member and said temperature responsive unit being substantially equal to balance static pres sures thereon, said frame including portions shielding said temperature responsive unit from velocity flow of the medium to be controlled, the base wall of said portion of said frame shielding said valve member from velocity flow in an axial direction of the medium to be controlled, said opening in the base wall and said valve port in the side wall of said portion of said frame, due to the spacing of said valve member from said walls, accommodating flow of the medium to be controlled to the interior of said valve member without substantial dynamic force, whereby static and dynamic forces on said valve member and said temperature responsive unit are substantially eliminated and said valve member is actuated by said temperature responsive unit solely in response to variations in the temperature of the medium to be controlled, the spacing of said valve member and said stem from said portion of said frame accommodating free movement of said valve member and seating of said valve member on its seat in response to temperature variations of the medium to be controlled despite the presence of foreign mat ter in the medium to be controlled and on the surfaces of said valve member, said stem and said portion of said frame.

2. A thermostat valve comprising a stationary frame including at one end thereof a cup-shaped portion of frusto-conical form having a valve port in the side wall thereof, a cup-shaped valve member of frusto-conical form and of a size larger than said portion of said frame freely slidable on said portion axially thereof, the walls of said valve member being freely spaced from the walls of said portion of said frame, said frame including a valve seat encircling said cup-shaped portion adjacent the open end thereof, said valve member normally seating at its open end on said seat to close the valve, the base wall of said portion of said frame having an axial opening therethrough, and a temperature responsive unit mounted on said frame to be disposed directly in the path of fluid iiOW of the medium to be controlled and including an stem extending freely through said opening in the base wall of said portion and connected axially to the base wall of said valve member, the opposed surfaces of said valve member and said temperature responsive unit being substantially equal to balance static pressures thereon, said frame including portions shielding said temperature responsive unit from velocity flow in an axial direction of the medium to be controlled, the base wall of said portion of said frame shielding said valve member from velocity flow in an axial direction of the medium to be controlled, said opening in the base wall and said valve port in the side wall of said portion of said frame, due to the spacing of said valve member from said walls, accommodating flow of the medium to be controlled to the interior of said valve member without substantial dynamic force, whereby static and dynamic forces on said valve member and said temperature responsive unit are substanti; ly eliminated and said valve member is actuated by said temperature responsive unit solely in responsive to variations in the temperature of the medium to be controlled, the frusto-conical forms of said valve member and said portion of said frame automatically centering said valve member on its seat, the clearance between said portion and said valve member and between said portion and said stem accommodating free movement of said valve member and seating of said valve member on its seat in response to temperature variations of the medium to be controlled despite the presence of foreign matter in the medium to be controlled and on the surfaces of said valve member, said stem and said portion of said frame.

3. A thermostat valve comprising a stamped sheet metal frame including an inlet at the lower end thereof and an integral inverted cup-shaped portion of frusto-conical form at the upper end thereof, said portion of said frame having outlet valve ports in the side wall thereof, a stamped sheet metal valve member, said valve member being of inverted cup-shape, of frusto-conical form and of a length greater than that of said portion of said frame. the inner diameter of said valve member adjacent the lower open end thereof being slightly greater than the maximum outer diameter of said cup-shaped portion of said frame, the taper of the frusto-conical side Wall of said valve member being steeper than that of the frustoconical side wall of said portion of said frame whereby said valve member fits freely over and is freely movable with respect to said portion of said frame, said frame ineluding a radial flange extending outwardly from the lower open end of said portion thereof to define a valve seat encircling said cup-shaped portion, said valve member being guided by the frusto-conical side wall of said portion of said frame into axial alignment with said valve seat, said valve member normally seating at its lower open end on said seat to close the valve, the base wall of said portion of said frame having an axial opening therethrough and tapering upwardly and outwardly therefrom, said frame including a downwardly depending support, and a liquid filled temperature responsive bellows fixed axially at its bottom on the upper surface of said support below said portion of said frame to be disposed directly in the path of fluid flow of the medium to be controlled, said support shielding said bellows from velocity flow of the medium to be controlled, said bellows including an axial stern extending freely upwardly through said opening in the base wall of said portion, said stem being fixed axially to the base wall of said valve member, tne downwardly facing surfaces of said valve member and the exposed upper surface of said bellows being of substantially equal area to balance static pressures thereon, the base wall of said portion of said frame shielding the downwardly facing surfaces of said valve member from velocity flow in an axial direction of the medium to be controlled and directing fluid flow transversely of the axis of said valve member, said opening in the base wall and said valve ports in the side wall of said portion of said frame, due to the spacing of said valve member from said Walls, accommodating flow of the medium to be controlled to the interior of said valve member without substantial dynamic force, whereby unbalanced static and dynamic forces on said valve member and said bellows --re substantially eliminated and said valve member is actuated solely by said bellows solely in response to variat ons the temperature of the medium to be controlled.

4. A thermostat valve comprising a stationary member to be disposed transversely of the path of flow of the medium to be controlled, said member includint a support to the inlet side thereof, a temperature responsive bellows rigidly supported axially of the path of flow at one end thereof on said support to the inlet side of said member to be disposed in and responsive to the temperature of the medium to be controlled, said support shielding said temperature responsive bellows from velocity flow of the medium to be controlled, the opposite end of said bellows being exposed and movable, a valve stem carried by said opposite end of said bellows and extending axially therefrom, said stationary member to the outlet side thereof including a generally cup-shaped portion having a frusto-conical side wall and an end Wall tapered inwardly of the cup toward said stem, the side wall of said member having an outlet valve port therein, the end wall of said member having an axial aperture therein of a size accommodating free passage therethrough of said valve stem, said stationary member including a radial fiange extending outwardly from the open end of said cup-shaped portion defining a valve seat encircling said side wall thereof, and a valve member positioned to the outlet side of said end wall of said cup-shaped portion, said valve member being of generally cup-shape, said valve stem extending freely through said aperture in said end wall of said member and being connected axially to the base wall of said valve member, the side wall portion of said valve member being trusts-conical and of an inner diameter adjacent its open end slightly greater than the maximum outer diameter of said cup-shaped portion of said stationary member, the frusto-conical side wall of said valve member being steeper and of a length greater than that of said cup-shaped portion of said stationary member whereby said valve member fits freely over the said cup-shaped portion of said stationary member, said valve member overlying the valve port in said stationary member and having a free edge normally engaging said valve seat to close the valve, said end wall of said stationary member shielding said valve member from velocity flow of the medium to be controlled, relatively restricted flow of the medium to be controlled to the interior of said valve member being accommodated through said ports and said aperture in said cup-shaped portion of said stationary member, said opposite surface of said bellows and the opposed inner surface portions of said valve member being of substantially equal area to balance static pressures thereon, whereby unbalanced static and dynamic pressures on said temperature responsive bellows and said valve member are eliminated and said valve member is actuated solely by said temperature responsive bellows solely in response to variations in the temperature of the medium to be controlled, the frustoconical side walls of said cup-shaped portion and said valve member automatically centering said valve member on its seat.

5. A thermostat valve as set forth in claim 1, including 14 a stop connected to said stem between said temperature responsive unit and the base wall of said portion of said frame, said stop being movable with said stem between the open and closed positions of said valve member and being engageable with said frame to define the full open position of said valve member.

References Cited in the file of this patent UNITED STATES PATENTS 1,784,061 Giesler Dec. 9, 1930 2,065,148 Nallinger Dec. 22, 1936 2,087,037 McCarthy July 13, 1937 2,137,136 Giesler Nov. 15, 1938 2,187,886 Mayo Jan. 23, 1940 2,336,858 Giesler Dec. 14, 1943 2,469,930 Payne May 10, 1949 2,489,209 Watkins Nov. 22, 1949 

